The pathological isoform of the prion protein (PrPres) can serve as a marker for prion diseases, but more practical tests are needed for preclinical diagnosis and sensitive detection of many prion infections. During FY2010, we 1) developed a new prion assay (called RT-QuIC) that is ultrasensitive, rapid and quantitative;2) adapted RT-QuIC to the detection of human, hamster, sheep and cervid prions;3) detected and quantitated prions in nasal lavages and cerebral spinal fluid from prion-infected hamsters and 4) developed methods for capturing and detecting prions from plasma samples;